1983 Yamaha 30EN Outboards Service Manual, Page 131Get this manual
CHARGING SYSTEM INSPECTION Lighting coil Refer to pageRectifier Check resistance and continuity using the Yamaha Pocket Tester (YU-33261) (1 scale) NOTE: _ 1Never connect the rectifier directly to the battery to check continuity2When testing, disconnect the battery terminals3When resistance is measured at less than 100 n, it can be said that there is continuity BATTERY If the battery shows the following defects, it should be replaced1The battery voltage will not rise to specific value nor will bubbles rise in any cell, even after many hours of charging2Sulfation of one or more calls is indicated by the plates turning white or an accumulation of material in the bottom of the cell 3Specific gravity readings after long, slow charge indicate cell to be lower than any others4Warpage or buckling of plates or insulator is evidentWARNING:
Rectifier resistance test 1Check the rectifier as specified using the pocket tester2If any element is broken, replace the entire unit
Battery fluid is poisonous and dangerous, causing severe burns, etcIt contains sulfuric acidAvoid contact with the skin, eyes, or clothingAntidote: EXTERNALFlush with waterINTERNALDrink large quantities of water or milkFollow with milk of magnesia, beaten eggs, or vegetable oilCall physician immediatelyEes: Flush with water for 15 minutes, and get prompt medical attentionBatteries produce explosive gassesKeep sparks, flame, cigarettes, etcawayVentilate when charging or using in an enclosed spaceAlways shield your eyes when working neara batteryKEEP OUT OF REACH OF CHILDRENThe service life of battery is usually two to three yearsLack of care, as described below, will shorten the life of the battery Negligence in keeping battery topped off with distilled water Battery left discharged Over-charging with heavy charge Freezing Filling with tap water or sulfuric acid containing impurities Improper charging voltage or current on new battery